c@351: /* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */
c@351: 
c@351: /*
c@351:     QM DSP library
c@351:     Centre for Digital Music, Queen Mary, University of London.
c@351:  
c@351:     This program is free software; you can redistribute it and/or
c@351:     modify it under the terms of the GNU General Public License as
c@351:     published by the Free Software Foundation; either version 2 of the
c@351:     License, or (at your option) any later version.  See the file
c@351:     COPYING included with this distribution for more information.
c@351: */
c@351: 
c@351: #ifndef SINC_WINDOW_H
c@351: #define SINC_WINDOW_H
c@351: 
c@351: #include <vector>
c@351: 
c@351: class SincWindow
c@351: {
c@351: public:
c@351:     /**
c@351:      * Construct a windower of the given length, containing the values
c@351:      * of sinc(x) with x=0 in the middle, i.e. at sample (length-1)/2
c@351:      * for odd or (length/2)+1 for even length, such that the distance
c@351:      * from -pi to pi (the nearest zero crossings either side of the
c@351:      * peak) is p samples.
c@351:      */
c@351:     SincWindow(int length, double p) : m_length(length), m_p(p) { init(); }
c@351: 
c@351:     int getLength() const {
c@351: 	return m_length;
c@351:     }
c@351: 
c@351:     const double *getWindow() const { 
c@351: 	return m_window.data();
c@351:     }
c@351: 
c@351:     void cut(double *src) const { 
c@351: 	cut(src, src); 
c@351:     }
c@351: 
c@351:     void cut(const double *src, double *dst) const {
c@351: 	for (int i = 0; i < m_length; ++i) {
c@351: 	    dst[i] = src[i] * m_window[i];
c@351: 	}
c@351:     }
c@351: 
c@351: private:
c@351:     int m_length;
c@351:     double m_p;
c@351:     std::vector<double> m_window;
c@351: 
c@351:     void init();
c@351: };
c@351: 
c@351: #endif